Aerosol delivery systems have been widely used for several decades to deliver a variety of consumer goods, including, for example, personal care items, paint, foods, and home care products. These systems utilize volatile propellants to push the product out of the aerosol containers. Aerosol technology has gained favor for being both effective and relatively inexpensive. The technology is not however without associated disadvantages. The release of traditionally used fluorocarbon and hydrocarbon type propellants into the atmospheres is one associated negative. Another disadvantage is that the aerosol containers are considered pressure vessels, which can necessitate extra safety equipment and procedures during its manufacture. The pressurized containers can also create concern for human injury if problems arise during storage, use, or disposal. And the high internal pressure accompanying many aerosol products has also limited the material and geometry options for the container.
Pump systems is one alternative to aerosols. Pump systems generally dispense a metered amount of a product. However consumers may have different requirements, and thus, difficulty arises in providing a proper metered amount that is satisfactory to all users. For example, one consumer may need to pump a dispenser two times to dispense their desired volume of product, and another consumer may only require one pump of the same dispenser. And if the desired volume is somewhere between pumps, the consumer may become frustrated in attempting to use the pump dispenser.
An approach has been developed to offer controlled dispensing similar to aerosols, but without many of the negatives associated with the same. This approach includes a collapsible container surrounded by an elastomeric band. A normally closed valve and an actuator assembly are affixed to the container. When the container is initially filled with product, it expands along with the surrounding elastomeric band. Potential energy is generated as the elastomeric band stretches. And when the actuator is operated to open the valve, the potential energy is converted to kinetic energy to dispense product out of the container until the actuator is disengaged. Examples of such a dispensing system are disclosed in U.S. Pat. Nos. 4,964,540 and 5,232,126. The predominant expansion and contraction of the elastomeric band in these systems is in the radial direction. As a result, a significant amount of product can be trapped in the closed end of the container, particularly where there are material property variances in the container and band, and where viscous products, such as, for example, gels are involved. Accordingly, there is room for improvement in the art.